There is some risk associated with buying anything, old or new.

I would argue that it can be riskier buying modern, firmware-driven, plastic, made-in-China equipment that will likely fail within 5 years and be completely unrepairable, however. As long as you mitigate your risk, buying older hi-fi gear should not be any riskier than buying new equipment. It can be less risky to buy well-cared-for older gear than newer stuff in terms of long-term reliability.

Much of the gear I work on from the ’70s and ’80s hasn’t failed, in 40+ years. It might need cleaning, service and adjustment, but everything does. A lot of newer gear (Cambridge, Marantz, NAD etc) fails after such a short time that it’s embarrassing, for everyone. This, for me, makes cheap new gear and sometimes even expensive stuff a riskier purchase.

You need to know what you are looking for and how to test older gear of course. This will involve listening to it and operating it. Beyond that, an inspection either pre or post-purchase is a very sensible idea and can potentially save a lot of money.

I offer inspections for my customers and run through every little detail on equipment they’ve bought, or are about to buy. Customers typically end up way in front, often saving far more than the cost of the inspection. This should come as no surprise of course, as it’s the same process we use when buying a pre-owned car for example, and brings the same benefits.

There are, unfortunately, people knowingly selling faulty gear, especially on GumTree. Be very careful and if in doubt, seek good advice.